Which is the best out of the box engine for a combat plane considering;

1. Cost
2. Performance (speed+torque)
3. Reliability
4. Durability (it's likely to take a few dirt naps)
5. Repairability (for replacing parts after the nap)

It will probably go on a Wild Thing / Crazy Thing...

Too bad you can only pick one. I would have voted for the TT as well as the Fox. I think the Tower price may be high. I bought my Fox .15 several years ago for about $50 from Morris Hobbies. But I don't think they sell them anymore. What does Quantum sell them for?

Had a really really old Fox .15 with the old style carb, wasn't too impressed with it overall... It was better than an old Enya I had, but still couldn't keep up with the rest of the guys...

If you are talking RCCA SSC? You are restricted by price 65.00 and RPM's 17500 with an MA 8X3 prop. I have a Magnum XL-15A BB ABC FSR and it keeps up with everybody.
Victor

The present Fox .15 is more powerfull than the TT, OS, and Magnum .15's. The older ones may not have been depending on which Fox .15 you had.

I had the IV with the oldest carb you can imagine. I talked to somoene at Fox and they recommended a newer model carb, but that would have been $40 and I can almost get a whole new engine for that....

I'm not really resricted by any particular rules, it's just some guys in my club that fight together. The only real rule is that it has to be a 15.\

Guess I forgot the Norvel Bigmig... I replaced the Rossi with that one...

Well my Fox is not really quite broken in and it will turn a MA 8-4 at over 15,500 RPM, over 1,000 RPM more than my TT.

On january '03 I decided to open "old boxes" with tools and engines after some 16 years being out of the hobby. My MVVS .15 was so gummed, that it took me several days to clean it, but finally it was possible to turn the shaft. I was still not sure if it is OK but I decided to put it to a small plane and try it.
The result: Friends of mine did not want to believe me the history of this engine. They were so impressed by sound, that they inmediatelly took a tach. It was turning 16.500 rev/min (MA 8x4)

The new one should easily turn 21.000 (MA 7x4)

see this thread [link]http://www.rcuniverse.com/forum/my_first_MVVS_%21/m_1634271/tm.htm[/link] on the MVVS .15 i've been playing with. the MAS 7x4 turnes about 600 rpm faster than the APC 7x4 in my tests.

also don't forget the conquest .15...unless mecoa stopped making them.


dave

THAT is what I am looking for. I read that post, and really since I have Zero knowledge of re-working an engine like that, it doesn't really do me allot of good. Guess that's why I am looking at the best overall "out of the box" engine. I was lost after about the second or third post. I understand most of what you're doing there, though I have no clue how nor the equipment to do so... I also read a thread somewhere talking about some problems with the MVVS .15 which is probably some of the issues you were correcting. How much would it cose to send an engine to someone and have them make the corrections like that ?

Rick

the MVVS in its stock form is still be a very hot engine, i'm just playing around with it to see how far i can go

any problems people have with them is most likely from running too much nitro/too much prop. in my tests i've used close to two liters of fuel so far and i'm still using the original plug. the engine is also very friendly and easy starting.

Pe Reivers [link]http://mvvs-nl.com/[/link] is one of the european dealers (and an RCU member) and aside from very good prices he also offers this engine with a modified crank and head button for more power. this should get you 19,000 with a MAS 7x5 using the tuned muffler. and you can get a lot more than that by running the engine as a rear exhaust with a Macs pipe.

for a full mod job it would be best to seek the help of the speed or boat freaks but it would cost a small fortune and you might end up sacrificing "streetability"


dave

Find a Cox Conquest .15.

It will out perform all engines on your list. I put one on a 2lb 4oz SPAD gnat with the Master Airscrew 8x3 and it had unlimited vertical, and flew right out of my hand without a toss.

They might outlaw it after you get one. I wish I could remember the source, but they were on sale recently somewhere for about $65

RJL / Mecoa is out of them, and I don't believe they will be having more made.

Do a search for Conquest and I'm sure you will find the link you are looking for.

Sheldons Hobbies had the Conquest for 64 bucks. I was just in there last night and it looked like they may have been out of them. I'm glad I bought a couple at that price. I have seen them go for over $100 on e-bay. It is one hot engine!!!!

Pete

I found one [link=http://www.mecoa.com/rjl/rjl.htm]HERE[/link] but they are out of stock and want more than I really want to pay for a combat engine. I checked Sheldons Hobbies but no luck there either. I'd buy one @ $65 today if I could find it and it's as hot as all the posts I could find said it was.....

Conquest engines are owned by RJL something or other now I think....
Here's what RJL had listed.

RJL C.15 R/C
Part #99-0501
Price: $139.99
Avail: out of stock



Zagnut,
One of the guys run this engine (thus why I felt compelled to poll it too) but another guy just bought the Magnum for $45 from Tower, put a mouse can on it and smokes us both. I tried an Enya 15, OLD OLD Fox 15 and the OS FP I have now... I can't get nearly the speed or vertical he has, but I would like to be able to smoke him for a while now lol.

modeltronics,

[link=http://www.rcuniverse.com/forum/m_1561311/mpage_1/key_conquest/anchor/tm.htm#1561311]Previous Post on another thread[/link]

So how many of these do you have?

I now have 2 NIB and one of the original Cox versions NIB.... I have 2 that I have run also. I get out to California near Sheldons very often for work. I think I have sent back about 5 from Sheldons for friends in Illinois that have asked me to pick them up. I was in there a couple of days ago and didn't see any more. You might want to give them a call to see if any are left.

Pete

I did try calling them, repeatedly! I called the 800 number and the 408 area code. BOTH said, "Thank You for calling blah blah phone service is not available" and then they hang up. I looked all over their site for an email and can't find that either. If they're trying not to sell anything, they're doing a great job at it....

As for the poll, it's not helping much lol. I added the Conquest (I know it's not really fair to add/change) but over 300 people have looked at this post and only 22 have actually taken the .00002 seconds it takes to hit the vote button lol. From what I've been able to read, the Conquest does seem to have the most plugs for being a hot engine out of the box. Guess thats why I can't find any....



Rick

I checked their website, and they no longer have it listed.

Dang, I wonder if anyone else still has these?

I'm down to one good one, but wouldn't mind having an extra.

Another engine that might make sense to try and find is a Nelson .15. I know some of the older pylon guys must still have some of these around that they would sell at a decent price. There is not much use for them without a QM15 class anymore. These engines blew the doors off the Conquest.

I'm in Claifornia right now and was trying to figure out something to do on the lunch break. I'll run over there (to Sheldons) and ask if they have any left. Give me about an hour and I will get back with you on here.

Pete

Just back from Sheldons. They are all out of Conquest 15s . They told me that they had a box of them that they couldn't sell. Then all of a sudden they had a big run on them a couple weeks back. My guess is that was about the time I put a post on here that they had them for a good price.

When I asked they guy behind the counter if he had any more, he knew who I was. He asked me how many of them I had. I didn't tell him I was sending them back to Illinois for my buddies. He thought it was real funny that they couldn't get rid of the Conquest 15s and then all at once everybody wanted one.

Pete

just how hot is the conquest .15?? i see lots of people quoting high rpm figures but never stating what brand of prop or exhaust setup is being used

how about some performance figures with the APC or MAS 7x4 or 7x5 props??

also i've looked over a stripped down conquest and didn't see anything in particular that should make it outperform the MVVS.


dave

Hey Zagnut,

With that OS I am running I've tried 7x6, 8x3, 8x4 and 8x5. I don't have tach numbers but it seems to do best with the 7x6 MAS or APC. Would droppin the pitch on a 7 actually do me any good for speed/torque or just give me more torque?

Rick

depends where your engine makes its power. if you're spinning the 7x6 at, say, 16,000 rpm you'll need to 20,000 on the 7x5 and 24,000 on the 7x4 to get the same speed...but you will get more thrust. can the OS .15FP spin those sizes that fast? i'd bet that it runs out of poop quite a ways before 20K due to conservative porting and would stick with what works best right now. if you need more speed the go up in pitch but down in diameter, but remember that you'll be giving up thrust (vertical) and acceleration. for more of that use less pitch and larger diameter.

the best way to know what really works on your engine/plane is to go flying with a bunch of different brands and sizes of props. while doing this you also have to do your best to ignore the sound from the engine as noise can be easily mistaken for speed


dave

Thats pretty much what I have done. I tried the props I listed both with and without the streamer. So far, the 7x6 MAS has been the best overall on Coolpower 20%. Typically I'm as fast without a streamer as he is with one. I don't know the *legal* lengths, but we use a 5' sting and about a 30' streamer... I just don't know very much about repairing these engines which is why I am really looking for the hottest out of the box engine. I might be able to work up a mouse can, but that would be about the extent of my tweaking.

Rick

I just got off the phone with the guy from [link=http://www.mecoa.com/rjl/rjl.htm]RJL Engines[/link]. They are out of stock and won't have any more for several weeks. Odds are I won't wait and will end up getting something else. I may try one later down the road, but the plane is built, ready to cover and will be in the air in the next week or so.

As I look at the other engines, several questions come to mind;

What's the difference between and engine that cost $45 and one that cost $110? The rpms aren't usually that much different, the bhp isn't that much different etc. There might be a slight increase, but overall is that little difference worth over 2x the money ?
As an example....

ie;